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Is Evolution Predictable?
An anonymous reader writes "C|Net is carrying a story about some research out of Rice University. They are exploring the possibility that we can predict the evolution of a species, given environmental factors." From the article: "Typically, the bacteria can continue to thrive when the temperature hits 73 degrees Celsius (163 degrees Fahrenheit). The experimental strain of bacteria contained a mutated version of a gene that, in the naturally occurring strain of the microbe, produces a protein that made existence possible. They then put these mutant strains in environments where the temperature rose slowly but steadily, and studied how different generations coped with the changing temperature. In the breeding that followed, millions of new mutations of the gene in question were produced, but only about 700 of those variants replicated some of the functionality of the naturally occurring gene."
since the human race is subject to the same laws of evolution i think this gene should be added to the human race so when global warming really starts to warm things up those humans that can use and evolve with this gene will survive...
Politics is Treachery, Religion is Brainwashing
I believe Darwin's comments have often been missunderstood because of an unfortunate choice of words. Evolution doesn't rely on the survival of the fittest, but of the most sustainable. If the mutant variants can sustain themselve they will survive, and be the DeFacto higher organism. Those that can't, don't, and become history.
... But this is not necessarily the case. Bacteria will almost certainly outlive humankind, for example.
Fittest suggests that you must be 'more' something. Stronger, faster, smarter,
Because you can - or because you should?
Obviously you can't predict evolution perfectly, but it is an extremely complicated (one could say the most complicated) mechanism in existence and so with a good understanding of the dynamics, organisms, their biology and environments you might very well be able to do something useful. For example the increasing of temperature gradually is in fact one such attempt.
If you had a very good understanding for example of a given gene and its mutations in an organism throughout history and in different evironments, you ought to be able to predict something of how it would act if inserted into another organism, and if it is a very successful gene it may have a great impact on "evolution". But it is probably 99% fantasy if you think those picture books illustrating "future creatures" are going to be what will come to pass.
The only meaningful answer to this question is, if you have full control over the environment can you direct evolution of an organism to develop in your desired direction. Of course this is possible, happens every day in the lab. But once you get away from talking about the evolution of say a given gene, and start talking about what a creature looks like, I think this is beyond our current knowledge though possibly not out of reach if we had far more powerful, half-sentient computers handling most of it. We are talking more about genetic engineering though now, not evolution. Possibly if we had a way to describe biomes and evolutionary stresses on organisms it might be possible to predict things like giraffes' necks elongating. Deducing the structure of an eye or a human's gait would seem to be far more difficult.
The effects of more novel mutations, though, are going to be much less predictable for the reasons you give.
I'm afraid you're another victim of popular media reporting on real science. From TFA, "Conceivably, if scientists can predict how the microbes will adapt to changes in their environment, they can develop antibiotics that won't be rapidly rendered ineffective by stronger, successive generations." This is undoubtedly the real motivation, not to test Darwin's celebrated theories.
Anyways, Darwin's theory doesn't really make any quantitative predictions. These guys are doing the basic science experiments that we haven't been able to do (not with much precision) until now b/c of technological limitations.
Now, as for the article... They perform and experiment TWICE and said that was enough to produce this theory. Because out of 2 million possible mutations, the same 6 occurred both times in large numbers.
Uhh... Don't forget CHANCE you fools. Twice is not very conclusive.
Uhh... It appeared in large numbers twice. Once was actually probably sufficient, but repeatability is always good. The probability of the mutation happening just twice amongst individual bacteria is astronomically small. It's a little like DNA tests in court - they're actually only probabilistically accurate to within about 1 in 10 billion, something on the order of one in the population of the world. It's just pretty damn unlikely that you're genetic partial-clone was also in the right place at the right time. If they can place it several times then it's especially damning.
Nevertheless, the experiments should and probably will be repeated.
m0nstr42.blogspot.com
We're all victims here, I think. From TFA: "Conceivably, if scientists can predict how the microbes will adapt to changes in their environment, they can develop antibiotics that won't be rapidly rendered ineffective by stronger, successive generations." That's probably the real goal, the message just gets mangled by some dumbassed reporter.
We've been working at predicting evolution and using evolutionary results to explain why animals have certain characteristics for quite some time. c.f. Evolutionary Game Theory, Behavioral Ecology, Adaptive Dynamics, etc. Of course these are mostly all theoretical results. The guys from TFA are doing experimental research that happens to verify the theories, which is in itself pretty cool - it's hard to do evolutionary experiments for obvious reasons. Using bacteria isn't a particularly new idea, but modern technology is enabling more sophisticated and precise experiments.
m0nstr42.blogspot.com
As for the ID attempt to bring about a paradigm shift in science: good luck. Seriously! The crux of ID is that of bias in observation of the natural world, and as such, ID attacks a fundamental difference in philosophy that separates spirituality from science: un-biased falsification. My mind spins at the notion of how that kind of paradigm shift would change what we call "science" - perhaps we could classify the current experiments involving neural imaging and Buddhist meditation as such. A revolutionary scientist is not attached to any particular scientific paradigm.
That being said, the only thing that creates new species is the human mind. Species do not exist: individual organisms exist. Individual organisms exhibit their characteristics (phenotype) based on the expression of their hereditary information (genotype in the form of nucleic acids) in their particular environment. The current model for biological evolution is really quite simple: it's a change in the frequency of alleles of genes in a population of organisms over multiple generations. And that brings me back to Darwin and your comment on the directionality of biological evolution. Of course it isn't random! J.T. Bonner's model for evolution is quite nice and has but a few basic ideas, as follow. The unit of evolution is the life cycle, not the individual. At the smallest stage in the life cycle, novel changes are introduced into the DNA. The life cycle develops through an interplay between its genetics and environment, during which time the weakest and unluckiest variations of the life cycle will die. The life cycle that develops to it's pseudo-largest stage will be able to reproduce, but will do so selectively. The frequency of alleles of genes in the population of life cycles changes in that moment of producing an offspring, and so evolution happens under the influence of both random and intelligent change.
But perhaps this is where the creationist root of ID takes charge, because ID always seems to want the intelligence to be outside the limits of the natural world. I think I'd have a lot less of a problem with the notion of intelligent design if the designer could be a sufficiently advanced product of biological evoltuion.
Actually I wonder about contamination... bacteria can and will take up stray DNA, and if the container was autoclaved after the first run, some of the mutant DNA would still be in there. The second batch of bacteria would take it up and act as if they'd invented it!
Jeremy
The summary of the research is pretty slim, but if we assume the reporter got it right (dangerous, I know):
If they replicated this twice, with the same dominant mutation, and the same derivatives, and the same two successful derivatives, then I don't think we need to wait until they complete 1000 reps of an experiment that takes weeks or months to complete before we accept that they are on to something. The probability of that happening by chance even twice may be enough to make this a significant result. On the other hand, if they only got as far as the same dominant and then the results were only similar, then maybe we could quibble about how many reps they should do.
Looking back at the original article, it describes the work as preliminary, and doesn't mention a publication, so I suspect that the additional replications may already be in progress in any case.
yp.
There are two kinds of evolution (not micro and macro, you silly creationists). Firstly, there is evolution in which the population responds to a simple change in the environment and has the option to either evolve or become crippled or even extinct. Slowly raising the temperature on a population of bacteria will obviously result in either the bacteria adapting or becomming extinct. This kind of evolution is very predictable.
The second kind of evolution is CREATIVE evolution. In this kind of evolution an old system or a new mutation is co-opted with some minor change into a feature or behaviour that increases chances of reproduction. Eventually this new feature may evolve to become a complex pathway or even a new organ. This kind of evolution is the way in which new complexity and new systems arise to take advantage of oppurtunities in the environment. It may even change the ecological niche of the eventual descendants. This kind of evolution has been demonstrated without guidance or a "goal state" in systems like Tierra where machine-code programs are allowed to self replicate (the system does not impose replication, they are written to replicate themselves using the instruction set) but an occasional bit is flipped to simulate mutation and crashed processes (equivalent of death) are removed. This is classic open-ended evolution. Google Tierra and read about it. Also Avida. Anyways....this kind of evolution is impossible to accurately predict. We have no way of knowing how man tentacles the octopus would evolve by looking at the ancestral slug. We cannot tell by looking at a fish that it's descendants will have lungs and walk on land. They may evolve into land creatures, and they may not, and they may not even use lungs. Sometimes evolution even stops and stagnates. Look at sharks, they have not evolved for millions of years even though they could certainly benefit from a four chambered heart or more intelligence. I would be impressed if someone could predict this kind of evolution, not the simple linear type where they either become heat-resistant or die.